Polo-like kinase 1 (Plk1) is one of the most attractive targets for anti-cancer therapy. Efforts to generate Plk1-specific inhibitors by targeting the catalytic activity of Plk1 have proven to be difficult due to similarities with the catalytic domains of other structurally related kinases. Here, we propose to develop a new class of mono-specific Plk1 inhibitors by employing a novel approach of targeting the non-catalytic, but functionally essential, PBD of Plk1. To this end, we have carried out a high throughput screen in collaboration with National Center for Advancing Translational Sciences (NCATS), Bethesda, MD. My NIH X01 grant proposal was approved for this particular project. From this screen, we have identified 3,000 compounds from a primary screen, which were narrowed down to the final 8 compounds through secondary medium throughput and tertiary cell-based assays. Currently, we are in the middle of further testing these compounds in cultured cells.